My father رحمه الله said, it was narrated to us by ʿAbd Allāh bin Jaʿfar al-Ḥumairi, who said – it was narrated to us by Aḥmed bin Moḥammed, from al-Ḥussain bin Sayf, from his brother, ʿAlī, from his father Sayf bin ʿUmayra, from al-Ṣādiq عليه السلام who said:

The The Messenger of Allāh صلى الله عليه وآله said: “There is no Muslim that says ‘There is no god but Allāh’ while raising his voice, except that [by the time] he completes [saying it], his sins strew under his feet, just as tree-leaves strew in front of it (the tree).”

أبي (ره) قال حدثنا عبد الله بن جعفر الحميري قال حدثني أحمد بن محمد عن الحسين بن سيف عن أخيه علي عن أبيه سيف بن عميرة عن الصادق عليه السلام قال قال رسول الله صلى الله عليه وآله ما من مسلم يقول لا إله إلا الله يرفع بها صوته فيفرغ حتى تناثرت ذنوبه تحت قدميه كما تناثر ورق الشجر تحتها